相关论文: Precise measurement of parity violation in polariz…
The quantity P_{mu}^{pi}xi, where xi is one of the muon decay parameters and $P_{\mu}^{\pi}$ is the degree of muon polarization in pion decay, has been measured. The value P_{mu}^{pi}xi = 1.0003 +- 0.0006 stat. +- 0.0038 syst. was obtained.…
The TWIST Collaboration has completed its measurement of the three muon decay parameters \rho, \delta, and P_\mu\xi. This paper describes our determination of \rho, which governs the shape of the overall momentum spectrum, and \delta, which…
The muon decay parameter delta characterizes momentum dependence of the parity-violating muon decay asymmetry. A new measurement of delta has been performed using the first physics data recorded by the TWIST experiment at TRIUMF. The…
The TWIST collaboration has performed new measurements of two of the parameters that describe muon decay: $\rho$, which governs the shape of the overall momentum spectrum, and $\delta$, which governs the momentum dependence of the…
The muon decay parameter delta has been measured by the TWIST collaboration. We find delta = 0.74964 +- 0.00066(stat.) +- 0.00112(syst.), consistent with the Standard Model value of 3/4. This result implies that the product Pmuxi of the…
A search for T-violating muon polarization in the $K^+ \to \pi^0 \mu^+\nu$ decay has been performed at KEK using stopped kaons. A new improved limit was obtained, $P_T= -0.0017 \pm 0.0023 (stat) \pm 0.0011 (syst)$, corresponding to a 90 %…
A search for T-violating transverse muon polarization ($P_T$) in the $K^{+}\to \pi^{0}\mu^{+}\nu$ decay was performed using kaon decays at rest. A new improved value, $P_T= -0.0017\pm 0.0023 (stat)\pm 0.0011 (syst)$, was obtained giving an…
The TRIUMF Weak Interaction Symmetry Test (TWIST) experiment was designed to test the standard model at high precision in the purely leptonic decay of polarized muons. A general four-fermion interaction model is used to describe the muon…
The TWIST Collaboration has completed a new measurement of the energy-angle spectrum of positrons from the decay of highly polarized muons. A simultaneous measurement of the muon decay parameters {\rho}, {\delta}, and (P_{\mu}){\xi} tests…
The TWIST experiment has made a precision measurement of three of the decay parameters in muon decay. The newest results are rho = 0.75014 +-0.00017(stat) +-0.00044(sys) +-0.00011(eta) and delta = 0.75067 +-0.00030(stat) +-0.00067(sys).…
We have examined the physics and the experimental feasibility of studying various kaon decay processes in which the polarization of a muon in the final state is measured. Valuable information on CP violation, the quark mixing (CKM) matrix,…
The potentiality of an experiment measuring the muon polarization in $K^+\rightarrow\pi^0\mu^+\nu_\mu$ at a $\phi$ factory is discussed, with particular attention to the possibility of revealing unexpected violation of Time reversal…
We have examined the physics and the experimental feasibility at the AGS of various kaon decay processes in which the polarization of a muon in the final state is measured. Valuable information on CP violation, the CKM matrix or new physics…
Measurement of the transverse muon polarization $P^{\bot}_{\mu}$ in the $K^+ \rightarrow \mu^+\nu\gamma$ decay will be attempted for the first time at the ongoing KEK E246 experiment and also at a proposed BNL experiment. We provide a…
We present the result of the first measurement of the T-violating muon polarization P_T in the decay K^+ --> mu^+ nu gamma. This polarization is sensitive to new sources of CP-violation in the Higgs sector. Using data accumulated in the…
The Michel parameter xi" has been determined from a measurement of the longitudinal polarization of positrons emitted in the decay of polarized and depolarized muons. The result, xi" = 0.981 +- 0.045stat +- 0.003syst, is consistent with the…
A new result for the transverse mu^+ polarization, P_T, in the decay K^+ --> pi^0 mu^+ nu has been obtained in the KEK E246 experiment. Combined with our earlier result, P_T = (-1.12 +- 2.17(stat) +- 0.90(syst))x10^{-3} and Im(\xi) = (-0.28…
The muon transverse polarization in the $K^+ \leftarrow \pi^0 \mu^+ \nu_\mu$ decay will be measured at the $10^{-4}$ level in forthcoming experiments. We compare the phenomenological perspectives with the theoretical predictions in…
We have examined the decay $K^0_L \to \pi^0 \mu^+ \mu^-$ in which the branching ratio, the muon energy asymmetry and the muon decay asymmetry could be measured. In particular, we find that within the Standard Model the longitudinal…
We have examined the decay $K^0_L \to \pi^0 \mu^+ \mu^-$ in which the branching ratio, the muon energy asymmetry and the muon decay asymmetry could be measured. In particular, we find that within the Standard Model the longitudinal…